Yahoo chief Marissa Mayer has proven to be a spark plug for the site and brand. Before she accepted the position as Chief Executive Officer (CEO) of Yahoo, the site was struggling to stay relevant and trying to figure out how best to market to its brand. Now two years later, Yahoo monthly active users are up 20 percent to 800 million around the world, and the company is processing 12,000 resumes a week.

That includes 350 million monthly active users on mobile, which is a testament to Mayer's ability to see the need to focus on mobile at a time when not all technology CEOs could see the writing on the wall. You could even argue that tech giants like Intel, AMD, and Microsoft all struggled to look past the desktop two years ago and all three are now trying to make up for lost time.

Image Source: Flickr (Fortune Live Media)

Mayer revealed the above statistics at TechCrunch Disrupt, adding that they're not artificially inflated with Tumblr's stats, a high-traffic site Yahoo acquired for $1 billion back in May of this year. She credits Yahoo's success to growth in its core products and services, most notably search and email.

Don't expect Mayer to let her early success go to her head. She has a longer-term vision for Yahoo and says it will be "three or more years" before the company is where she wants it to be, which will require focusing on people, products, traffic, and revenue.

Given her track record, it's perhaps too bad for Microsoft that Steve Ballmer didn't decide to retire when Mayer was still available.